Apparatus for the control of highway crossing signals



July 6, 1937. J. .1. VANHORN 2,085,932

'- APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Original FiledJan. 11, 1956 0 i l i 1b Ml B FF C T1 00]: 5 2m A5272 D [mz ammt AINVENTOR Jamerl [@121101 12 H16 ATTORN EY Patented July 6, 1937 UNITEDST APPARATUS FOR THE CGNTROL OF HIGH- WAY CROSSING SIGNALS Originalapplication January 11, 1936, Serial No.

58,716. Divided and this application October 27 1936, Serial No. 107,848

5 Claims.

My invention relates to apparatus controlled by a train approaching ahighway crossing for governing the operation of the highway crossing.signal.

The present application is a division of my copending application SerialNo. 58,716, filed January 11, 1936.

A feature of my invention is the provision of novel and improvedapparatus controlled by a train approaching a highway crossing forpreventing a continued operation of the highway crossing signal in theevent the train should stop within the control section, and forrestarting the operation of the signal when the train resumes itsmovement. Other features and advantages of my invention will appear asthe specification progresses.

I will describe one form of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic View of one form of apparatusembodying my invention wherein operation of a highway crossing signal iscontrolled by a train approaching the intersection from one directiononly.

Referring to the drawing, the reference characters la and I b designatethe rails of a stretch of railway over which traffic normally moves inthe direction indicated by the arrow, and which rails are intersected bya highway H. A highway crossing signal S is located adjacent theintersection. I his signal S may take any one of several different formsfor highway crossing signals and, as here shown, is an audible signal inthe form of an electric bell. The immediate control of signal S iseifected through the medium of a control relay SC the arrangement beingsuch that when relay SC is deenergized and its back contact 2% closedcurrent is supplied to signal S over a simple circuit and a warning issounded. The. manner of controlling the relay SC will be describedhereinafter.

The track rails is and lb are divided by insulated rail joints 2 to formthree track sections 133T, AST and 2T which a train traverses in theorder named in approaching the highway when traveling in the normaldirection oftrafiic. As here shown, the exit end of section 2T isadjacent the highway H. The combined length of these three tracksections is sufiicient to provide a desired warning period for thesignal S prior to the arrival of a train at the intersection whenoperation of the signal is initiated as the train enters the sectionBST. A wayside station RWS, such for example as a passenger or freightATNT orricr. v

station, is associated with the track section A3T I and, as here shown,is near the junctionof sec tions A31 and 133T. Each track section isprovided with a track circuit which includes a source of current such asa battery 3 connected across the rails at one end of the section, and atrack relay R. plus a prefix corresponding to the associated sectionconnected across the rails at the other end of the section. V

A track instrument designated by the reference character Mtisoperatively connected with the rail in at a selected point for actuationthereof in response to the wheels of a train passing over the point atwhich the track instrument is located. This track instrument is sodesigned that it has the characteristic of increasing its resistanceinresponse to vibration of a train passing trodes through the carbongranules is relatively a low but when the microphone is vibrated by apassing train and the carbon granules are agitated the resistancebetween the electrodes becomes several times the normal resistance. Itwill be understood, of course, that my invention is not limited to thisone form of trackinstrument and other forms may be used. The trackinstrument Ml is located in the vicinity of the station BWS and as hereshown is connected with the track rail near the exit of section 331. The4 track section AtT is preferably short and track instrument Ml isvibrated while a train is moving in section A3T as well as just prior tooccu pancy of section AST. Although only one track instrument is shown,it will be understood that additional instruments may be spaced alongsection A31 and vibration of at least one instrument while a train ismoving in the'section is assured.

A relay D is controlled by the track instrument M! and to that end isprovided with a circuit extending from the B terminal of any convenientsource of current, such as a battery not shown, through theelectrodes'and carbon granules of the track instrument Ml, winding ofrelay D and to the opposite terminal C of the same source of current.The parts are so proportioned that when the track instrument MI is atrest, the flow of current is sufficient to effectively energize relay Dand its front contact 29 is closed, but when the track instrument isvibrated by a passing train the flow of current is reduced and the relayis deenergized, or at least is not sulficiently energized, and its frontcontact 29 is opened. Although only one track instrument is shown forcontrolling relay D, it will be understood that, if additionalinstruments are located at selected points along the track section A3Tas pointed out hereinbefore, then such additional track instruments willbe serially connected in the circuit of relay D.

The signal control relay SC is normally energized over a normally closedcircuit passing from the terminal B of the current source over frontcontacts 25, 26, and 2'! of track relays B3TR, ASTR, and ZTR,respectively, winding of relay SC and to the opposite terminal C of thecurrent source. An alternative energizing circuit for relay SC isprovided which extends from the B battery terminal over front contact 29of relay D, back contact 26 of relay A3TR, front contact 27 of relay2TH, winding of relay SC and to the C battery terminal. It follows thatwhen all three track sections 2T, ABT and BST are unoccupied and thetrack relays ZTR, ASTR. and B3TR are picked up, or when the section A3Tis occupied and section 2T is unoccupied and relay D is picked up, therelay SC is energized, but that when section 2T is occupied, or whensection A3T is occupied and relay D is down, or when section B3T isoccupied and sections ET and A3T are unoccupied, the relay SC isdeenergized. The relay SC is made slightly slow to pick up in character,and consequently it will not pick up in response to pulsating energywhich may be supplied to it by rely D momentarily picking up when atrain in sections AST and B31 is slowly passing over a track instrument.

When a train approaching the intersection enters section 133T, relayB3TR releases and at front contact opens the normal energizing circuitfor relay SC so that relay SC releases and closes its back contact 24 tostart the operation of signal S. Just before the train enters sectionAST, track instrument Mi becomes active and causes relay D to releaseand open a point in the alternative circuit for relay SC at frontcontact 29. As the train enters section A3T track relay A3TR releases,and at its back contact 26 closes a point in the alternative energizingcircuit for relay SC and at its front contact 26 opens the normalcircuit for relay SC. As stated hereinbefore, the track section A3T willbe relatively short, or other track instruments will be spaced alongsection A3T and interposed in the circuit for relay D in series withtrack instrument MI, and hence it will be apparent that so long as thetrain continues moving relay D will remain deenergized and operation ofthe signal S will continue, while the train is passing through sectionA31. When the train enters section 2T the relay 2TB. will be released toopen contact 2'! interposed in both the normal and the alternativecircuits of relay SC and operation of signal S will be effected untilthe train passes over the intersection and vacates section 2T. If thetrain stops at the station RWS the relay D will pick up and close thealternative circuit for relay SC at front contact 29, to stop theoperation of the signal during the time the train remains standing. Thetrain, upon starting away from the station, will cause the trackinstrument to be vibrated with the result that relay D will be released,opening the alternative circuit of relay SC, and operation of the signalS will be started again. The operation will continue until the trainpasses over the intersection and vacates section 2T.

Although I have herein shown and described only one form of apparatusembodying my invention, it is to be understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track divided into three tracksections each provided with a track circuit including a track relay andone section of which is intersected by a highway, a highway crossingsignal at the intersection, a track instrument associated with a rail ofthe intermediate of said sections and of a type which is instrument, andan energizing circuit for said control relay including contacts of thetrack relays of the intersected and intermediate of said sections and acontact of said auxiliary relay respectively.

2. In combination; a stretch of railway track divided into a first, asecond and a third track section and each provided with a track circuitincluding a track relay; said first section intersected by a highway, ahighway crossing signal located at the intersection, a track instrumentlocated at a station associated with said second and third tracksections, an auxiliary relay controlled by said instrument anddeenergized when a train is moving in the vicinity of the station, acontrol relay for governing the operation of the signal, a normallyclosed circuit for said control relay and including a front contact foreach of said track relays, and an alternative circuit for said controlrelay including a front contact of the auxiliary relay and a backcontact of the track relay for the second section as well as a frontcontact of the track relay for the first section.

3. In combination; a stretch of railway track divided into a first, asecond and a third track section and each provided with a track circuitincluding a track relay; said first section intersected by a highway, ahighway crossing signal located at the intersection, a train actuatedmeans associated with the second section and actuated while a train isin motion in that section, an auxiliary relay controlled by said trainactuated means and deenergized when said means is actuated, a controlrelay for governing the operation of the signal, a normal circuit forsaid control relay including a front contact of each of said trackrelays, and an alternative circuit for said control relay including afront contact of the auxiliary relay and a back contact of the trackrelay of the second sections as well as a front contact of the trackrelay for the first section.

4. In combination; a stretch of railway track divided into a first, asecond and .a third track section and each provided with a track circuitincluding a track relay; said first section intersected by a highway, ahighway crossing signal located at the intersection, a stationassociated with the second section, train actuated means associated withthetrack in the vicinity of the station and of the type which isactuated only by a moving train in the vicinity, an auxiliary relaycontrolled by said train actuated means and deenergized when said meansis actuated, an operating circuit of said signal, means including afront contact of each of the track relays for modifying the condition ofthe operating circuit as required to operate the signal in response tooccupancy of any one of the three track sections, and other meansincluding a front contact 7 of the auxiliary relay and a back contact ofthe track relay of the second section to remove such modified conditionof the operating circuit while a train is standing at the station.

' 5. In combination; a stretch of railway track divided into a first, asecond and a third track section and each provided with a track circuitincluding artrack relay; said first section intersected by a highway andsaid second section relatively short, a highway crossing signal locatedat the intersection, a station located along the second'section, a trackinstrument associated with a rail adjacent the junctionfof the secondandthird sections and of a type which is actuated only by a moving trainin the vicinity, an auxiliary relay controlled by saidtrack instrument,an operating circuit for the signal, means including a front contact ofeach of the track relays for modifying the condition of the operat-

